求下列初值问题的解 :[tex=14.571x1.571]lWHArqZ/HNZi9yRwpjL5D23Nwsf5DiGV845eswbdpQbvz50b7fteuXNViq+TCtjwFZ8EGD7wXnVQ7DRlSJVtIccxtG65dembosB8BJi4rCU=[/tex] .

下列三种配合物中, 推测哪一种配合物会吸收最高频率的光：[tex=14.571x1.571]mIpaviRoWnrq12gi6JSQ5ZpZHkof9BhQl/QFBB1VNjYzNHgpjXkLbkiWoM+8NxD8xvPOwqo7IjxLXWT80+Q5+QBC1UPrHaPqWrQGRDkWNaPUAe3SM0TkZDFchDy8ryovRFLaKkxw0421bFAv1G8ShjjT94xB/QMjz4Uol88+Ze3jNnlH9AVzIO/c/p5HFsXf[/tex]

设 [tex=3.357x1.0]LPsc8hYEuA1nbYt0TU9lDppQI6ybiLMW1XeU0XTFQwI=[/tex] 是多项式 [tex=6.357x1.357]YRpc3F4ZBjLi3gtiGhLi6nTSjbQ4xJfchjVbxUPfRwU=[/tex] 的 3 个根, 则 [tex=14.571x1.571]mTfiTM3967YiG1EDA6783DAq7JYgJBoreIHJsxOuiph86HptOzIcFIXMNGiv1Fnjg/5a66A81AX42dqhxWmvr0zz2dvcSrsl1pSu8POtUnnqEDVoYHfc1J8ft4yA3kPu[/tex][input=type:blank,size:4][/input]

图 [tex=2.286x1.143]CSham/vPIP0iNbtoEXmen+wgEPesQ3V6WpoACfeAWJE=[/tex] 所示的刚架自重不计。已知 [tex=14.571x1.571]0QSXQtXu19o7WkYPQgZWBqgZbtBOxnZbWawClR15Q3VRTSyoLb5ixxaCbfFKrase0OfKjV+Ew1BBfp5Os2vKxsQF15Kw86r0yJZgDqq1yMAEtqPFD7hmDJZNf+2zaWJl[/tex], [tex=2.0x1.214]Jup0ChK5Oj/wyQ52yLmQHQ==[/tex] 为光滑铰链。试求支座 [tex=0.786x1.0]Yn3GgEZev6SOu2r4v1WnCw==[/tex] 的约束力。[img=979x521]179d239df1f30e4.png[/img]

图 [tex=2.286x1.143]CSham/vPIP0iNbtoEXmen+wgEPesQ3V6WpoACfeAWJE=[/tex] 所示的刚架自重不计。已知 [tex=14.571x1.571]0QSXQtXu19o7WkYPQgZWBqgZbtBOxnZbWawClR15Q3VRTSyoLb5ixxaCbfFKrase0OfKjV+Ew1BBfp5Os2vKxsQF15Kw86r0yJZgDqq1yMAEtqPFD7hmDJZNf+2zaWJl[/tex], [tex=2.0x1.214]Jup0ChK5Oj/wyQ52yLmQHQ==[/tex] 为光滑铰链。试求支座 [tex=0.786x1.0]ri6gmnf1+J9dGqG5/1sV6A==[/tex] 的约束力。[img=979x521]179d239df1f30e4.png[/img]

下列变量组（）是一个闭回路。 A: {x，x，x，x，x，x} B: {x，x，x，x，x} C: {x，x，x，x，x，x} D: {x，x，x，x，x，x}

以下谓词蕴含式正确的是（）: (∀x) (A(x)→B(x))=>( ∀x)A(x)→(∀x)B(x)|(∀x) (A(x)↔B(x))=>( ∀x)A(x)↔(∀x)B(x)|(∀x)A(x)∨(∀x)B(x)=>( ∀x) (A(x)∨B(x))|(∃x) (A(x)∧B(x))=>(∃x)A(x)∧(∃x)B(x)

以下谓词蕴含式正确的是（）: (?x) (A(x)→B(x))=>( ?x)A(x)→(?x)B(x)|(?x) (A(x)?B(x))=>( ?x)A(x)?(?x)B(x)|(?x)A(x)∨(?x)B(x)=>( ?x) (A(x)∨B(x))|(?x) (A(x)∧B(x))=>(?x)A(x)∧(?x)B(x)

下列式中错误的是： A: (∀x)(A(x)Úp(x)) Û (∀x)A(x)Ú (∀x)p(x) B: ($x)A(x) Ù p Û ($x)(A(x) Ù p ) C: (∀x)(A(x)ÚB(x)) Þ (∀x)A(x)Ú( ∀x)B(x) D: ($x)(A(x)ÙB(x)) Þ ($x)A(x)Ù( $x)B(x)

判断下列推证是否正确。 (∀x)(A(x)→B(x))⇔(∀x)(￢A(x)∨B(x)) ⇔(∀x)￢( A(x)∧￢B(x) ) ⇔￢(∃x) ( A(x)∧￢B(x) ) ⇔￢( (∃x)A(x)∧(∃x)￢B(x) ) ⇔￢(∃x)A(x)∨￢(∃x)￢B(x) ⇔￢(∃x)A(x)∨(∀x)B(x) ⇔(∃x)A(x)→(∀x)B(x)